Yarn of staple fibers from multi-filaments by stretching and controlled breaking and articles made therefrom

ABSTRACT

A single-strand yarn includes a plurality of intimately associated staple fibers made from N strands of multi-filaments by stretching and controlled breaking, and then spun by a spinning process, where N is a natural number. Within the single-strand yarn of a sampling length according to the invention, a ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length to the total number of the staple fibers, is equal to or greater than 60%. The sampling length is equal to or less than 10 meters. The setup fiber length is equal to or larger than 65 mm. The dispersion of the weight distribution in the average length of the single-strand yarn according to the invention is equal to or less than 60%.

CROSS-REFERENCE TO RELATED APPLICATION

This utility application claims priority to Taiwan Application Serial Number 109125696, filed Jul. 30, 2020, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The invention relates to a single-strand yarn and a plied yarn made from at least one strand of multi-filaments by stretching and controlled breaking, and a textile article made therefrom, and more in particular, to a single-strand yarn or a plied yarn having high strength and high diameter uniformity and being made from a plurality of intimately associated staple fibers made from multi-filaments by stretching and controlled breaking, and a textile article made therefrom.

2. Description of the Prior Art

Continuous filaments made of various materials will be further broken into staple fibers and spun into yarns due to application and cost considerations. These yarns spun from discontinuous staple fibers necessarily have poorer properties than continuous multi-filaments of the same diameter and the same material, including strength and diameter uniformity because of discontinuous staple fiber distribution. Stretch-break spinning way is to improve the spinning technology to obtain the properties of yarns of staple fibers closer to those of multi-filaments of the same fineness and the same material, especially more important for high-performance fibers, such as carbon fibers, metal fibers, aromatic polyamide fibers, ultra-high molecular weight polyethylene (UHMWPE) fibers, polybenzoxazol (PBO) fibers, polyvinylcarbazole fibers, glass fibers, etc.

Taking Kevlar® fiber (aromatic polyamide synthetic fiber) manufactured by DuPont Corp. as an example, a 350D (denier) single-strand of Kevlar® multi-filaments has the strength of up to 10 kg. However, a 350D single-strand of Kevlar® multi-filaments is very expensive. In commercial applications, such expensive yarn is rarely used to make textiles. Instead, the traditional twisted yarn made from a plurality of Kevlar® spun yarn is used to make textiles. The twisted yarn of Kevlar® staple fibers with a fineness equivalent to the fineness of a 350D single-strand of Kevlar® multi-filaments is a double-strand yarn of 30Ne, but its strength is only 3.6˜4 kg.

In order to improve the strength and diameter uniformity of the yarn formed by twisting multiple staple fibers, one prior art breaks multi-filaments into staple fibers by the stretch-breaking way, and then twist staple fibers into yarns. The stretch-breaking way is to feed multi-filaments into the stretch-breaking machine to obtain the stretch-broken fibers. The prior art breaking machine is composed of multiple sets of rollers that paired combinations are a serial up and down roller pairs, or combinations are arranged triangularly with one roller up and two rollers down or two rollers up and one roller down, or a mixed arrangement with roller pairs and triangle combinations. The distance between the multiple sets of rollers in the stretch-breaking machine is set as the length of the broken fiber. The multi-filaments are broken by the speed difference of the multiple sets of rollers to obtain a broken sliver with a fiber length distribution. The broken sliver obtains a length weight distribution per unit sampling length. The broken sliver is then fed into the spinning machine, and can be spun directly into a single-strand yarn.

According to the theory of spinning engineering, the strength uniformity of a single-strand yarn mainly depends on the fiber length distribution in the single-strand yarn. Moreover, the diameter uniformity of a single-strand yarn mainly depends on the weight distribution in the average length of the single-strand yarn. Firstly, under a fixed yarn length, because the length of the broken fibers is not uniform, the fiber length distribution in the yarns will have a degree of dispersion. An ideal breaking length of the broken fiber is called a setup fiber length. The setup fiber length is equal to the distance from the grip point of the front exit roller of the spinning machine to the grip point of the rear roller. The dispersion of the fiber length distribution of in the yarn refers to the ratio of the number of staple fibers, whose length is equal to or greater than 60% of the setup fiber length, to the total number of staple fibers. The lower the ratio, the greater the dispersion of the fiber length distribution in the yarn is. Larger dispersion of the fiber length distribution in the yarn means that the fiber length uniformity in the single-strand yarn is worse. The worse the fiber length uniformity is, the worse the cohesive force between the fibers will be. And, the worse the cohesion force will seriously affect the stress transmission to result in poorer strength uniformity. On the contrary, the smaller the dispersion of the fiber the fiber length distribution in the yarn is, the better the strength uniformity of the yarn will be. Secondly, under a fixed setup fiber length, the weight distribution of the average length of the single-strand yarn will also have a degree of dispersion. The weight of the average length of a single-strand yarn is defined as the gram weight of the single-strand yarn per meter. The dispersion of the weight distribution of the average length of a single-strand yarn refers to the deviation range of the individual measured weight of the average length from the average weight of the average length under multiple sampling times. The greater the dispersion of the weight distribution of the average length of a single-strand yarn, the greater the difference in fiber quantity distribution per unit volume of the single-strand yarn is. It is mainly because there are too many free fibers. Free fibers will migrate freely during the spinning process. This free migration of the free fibers is uncontrollable, so it will result in uneven yarn, neps or knots during the spinning process. The formation of uneven yarn, neps and knots seriously affects the diameter uniformity of the yarn. On the contrary, the smaller the dispersion of the weight distribution of the average length of a single-strand yarn, the better the diameter uniformity of the single-strand yarn is.

Therefore, the traditional spinning process is actually to control the dispersion of the fiber length distribution and the dispersion of the weight distribution of the average length of the yarn. Therefore, the traditional spinning technology needs to go through the procedures of opening and picking process, carding process, drawing process, roving process, and spinning process to reduce the above-mentioned two dispersions. Differently, the stretch-break spinning technology only needs to go through the stretch-breaking process, the drawing process and the spinning process. As the process is shortened, the stretch-break spinning technology increases the above two dispersions. Therefore, the dispersion of the fiber length distribution and the dispersion of the weight distribution of the average length of the yarn spun by the stretch-break way are much higher than those of the yarn spun by the traditional spinning technology.

In addition, in traditional spinning technology, due to the efficiency requirements of quality control sampling, the weight distribution of the average length of the yarn and the length distribution of the staple fibers are both too long in the sampling length of the test. Generally, the sampling length for testing is 30˜100 m, which has little effect on the traditional spinning process that has achieved good control of the mentioned-above dispersions. But, for yarns that have only undergone stretch-breaking process, drawing process and spinning process with high dispersions, too long sampling length will conceal the problem of dispersions and fail to show the true strength and diameter uniformity of the yarn, and eventually will lead to a large gap between the statistical value and the actual application.

At present, stretch-break spinning technology is mainly used in spinning of high-performance fibers, such as carbon fibers, metal fibers, aromatic polyamide fibers, ultra-high molecular weight polyethylene fibers, polybenzoxazol fibers, polyvinylcarbazole fibers, or glass fiber. Because high-performance fibers are costly in the production of small-diameter multi-filaments, the relatively low-cost large-diameter multi-filaments of such high-performance fiber can be used to be spun into finer yarn of staple fibers of such high-performance fiber through stretch-break spinning. At the same time, stretch-break spinning technology makes it easier to produce yarns of long staple fibers. Compared to the strength of continuous multi-filaments, the longer the length of the long staple fibers, the closer the strength of the resulting yarn will be to the strength of continuous multi-filaments. Therefore, considering the manufacturing cost and strength of the yarn, in textile manufacturing, the yarn produced by the stretch-break spinning technology has the opportunity to replace the small-diameter multi-filaments. For example, a double-strand yarn of 50Ne, spun from stretch-broken aromatic polyamide staple fibers, replaces a 200D single-strand of aromatic polyamide multi-filaments. However, if the length of the stretch-broken staple fibers is too short, the strength loss of the yarn spun from the stretch-broken staple fibers will increase. Therefore, increasing the length of the stretch-broken staple fibers is very important for the stretch-break spinning process of the high-performance fibers. In general, the longer the length of the stretch-broken staple fibers, the less the strength loss of the yarn spun from the stretch-broken staple fibers will be. The yarn of high-performance fibers spun by the stretch-break spinning process can even reach more than 70% of the strength of the single-strand yarn of high-performance multi-filaments with the same fineness. In addition to the control of the length of the stretch-broken staple fibers, the better the control of the above two dispersions is needed, so that the strength and diameter uniformity of the yarn formed by the stretch-breaking spinning process can be closer to those of the single-strand yarn of multi-filament with the same fineness.

Please refer to U.S. Pat. No. 482,563 for the prior art of forming yarns with high-performance fibers using the stretch-break spinning technology. U.S. Pat. No. 482,563 discloses the use of a stretch-break spinning technology to make yarns of carbon fibers and control the average length of the stretch-broken carbon fibers. However, judging by the theory of yarn strength uniformity, the average length of the stretch-broken fibers is not a key factor affecting the strength of the yarn spun from the stretch-broken fibers. The yarn formation of the stretch-broken fibers should be controlled by the dispersion of the fiber length distribution in the yarn. Because stretch-break spinning technology of the prior art has poor control over the dispersion of the fiber length distribution in the yarn, the use of a stretch-break spinning technology, disclosed by U.S. Pat. No. 482,563 to make the yarns of the stretch-broken carbon fibers and to control the average length of the stretch-broken carbon fibers, cannot ensure the strength of the yarns of carbon fibers.

In addition, with regard to textile articles made from high-performance fibers using the stretch-break spinning technology to form yarns and then woven, due to the problem of yarn diameter uniformity, the smoothness of the textile articles will be seriously affected, which will cause problems in their use. For related prior art, please refer to the U.S. Pat. No. 6,756,330 and U.S. patent publication no. 20130008209. Both of these patents disclose yarns of stretch-broken metal fibers and textile articles woven from the yarns by a knitting process. The knitted textile article is used as high-temperature separation cloth for covering molds and tempering or press-on rings which are utilized in the process of forming glass plates, or for covering the means of transport by which glass plates are moved during the forming process. In practice, the applicant of these two patent applications, Bekaert, uses stainless steel fibers to manufacture the above knitted fabrics, and currently uses yarns spun from stretch-broken stainless steel fibers to be knitted into knitted fabrics on the consideration of the strength and cost of the knitted fabrics. U.S. Pat. No. 6,756,330 discloses increasing stitches per square centimeter or density of the fabric to achieve the required smoothness of the knitted fabric. The smoother knitted fabric is used to reduce the risks for markings occurred on the glass plate during pressing. U.S. patent publication no. 20130008209 discloses a knitted fabric knitted with yarns spun from stretch-broken stainless steel fibers, and the yarns include at least three bundles or single yarns. The bundles or single yarns have an equivalent bundle diameter, which are equal or differ maximally 40%, to achieve the required smoothness of the knitted fabric. The smoother knitted fabric is used to reduce the risks for the markings occurred on the glass plate during pressing. However, judging by the theory of yarn diameter uniformity, it is the yarn diameter uniformity that mainly affects the smoothness of the knitted fabric, not the stitches per square centimeter or density of the fabric and the difference of equivalent bundle diameter between the bundles or the single yarns.

It is conceivable that if yarns with uneven finesses are knitted into a knitted fabric, the uneven finesses of the yarns themselves will cause irregular undulations on the surface of the knitted fabric. Therefore, increasing the yarn density of knitted fabrics or reducing the difference of equivalent bundle diameter between the bundles or the single yarns cannot change the irregular undulations of the fabric. At present, the number of neps on the surface of a knitted fabric made from stainless steel fiber yarns of stretch-broken metal fibers is more than 50/m².

SUMMARY OF THE INVENTION

Accordingly, one scope of the invention is to a single-strand yarn and a plied yarn having high strength and high diameter uniformity and being made from a plurality of intimately associated staple fibers made from multi-filaments by stretching and controlled breaking, and a textile article made therefrom. The textile article produced from the yarns made from the stretch-broken staple fibers according to the invention has better smoothness.

A single-strand yarn according to a first preferred embodiment of the invention includes a plurality of intimately associated staple fibers. The plurality of intimately associated staple fibers are made from N strands of first multi-filaments by stretching and controlled breaking, and then are spun by a spinning process, where N is a natural number. Within the single-strand yarn of a sampling length, a ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length, to the total number of the staple fibers is equal to or greater than 60%. The sampling length is equal to or less than 10 meters. The setup fiber length is equal to or larger than 65 mm. A dispersion of a weight distribution in an average length of said single-strand yarn is equal to or less than 60%. The N strands of first multi-filaments can be made of at least one selected from the group consisting of copper, CuNi alloys, CuNiSi alloys, CuNiZn alloys, CuNiSn alloys, CuCr alloys, CuAg alloys, CuW alloys, FeCrAl alloys, silver, gold, lead, zinc, aluminum, nickel, brass, phosphor bronze, beryllium copper, nichrome, tantalum, tungsten, platinum, palladium, stainless steels, 316L stainless steel, titanium, titanium alloys, Ni—Cr—Mo—W alloy, zirconium, zirconium alloys, HASTELLOY® alloys, Nickel alloys, MONEL® alloys, ICONEL® alloys, FERRALIUM® alloy, NITRONIC® alloys, CARPENTER® alloy, polyester, polyamide, aramid polyamide, polyacrylic, polyethylene, ultra-high molecular weight polyethylene, polypropylene, cellulose, protein, elastomeric, polytetrafluoroethylene, polybenzoxazol (PBO), polyvinylcarbazole, polyetherketone, carbon, bamboo charcoal, glass, or other conductive or non-conductive materials.

In one embodiment, a single-strand of second multi-filaments is formed of the at least one material forming the N strands of first multi-filaments. A first fineness of the single-strand yarn is identical to a second fineness of the single-strand of second multi-filaments. The single-strand yarn has a first strength, the single-strand of second multi-filaments has a second strength, and the first strength is equal to or greater than 70% of the second strength.

A plied yarn according to a second preferred embodiment of the invention includes M single-strand yarns, where M is an integer equal to or larger than 2. The M single-strand yarns are doubled or twisted together. Each single-strand yarn a plurality includes a plurality of intimately associated staple fibers. The plurality of intimately associated staple fibers are made from N strands of first multi-filaments by stretching and controlled breaking, and then are spun by a spinning process, where N is a natural number. Within said one single-strand yarn of a sampling length, a ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length, to the total number of the staple fibers is equal to or greater than 60%. The sampling length is equal to or less than 10 meters. The setup fiber length is equal to or larger than 65 mm. A dispersion of a weight distribution in an average length of said one single-strand yarn is equal to or less than 60%. The N strands of first multi-filaments can be made of at least one selected from the group consisting of copper, CuNi alloys, CuNiSi alloys, CuNiZn alloys, CuNiSn alloys, CuCr alloys, CuAg alloys, CuW alloys, FeCrAl alloys, silver, gold, lead, zinc, aluminum, nickel, brass, phosphor bronze, beryllium copper, nichrome, tantalum, tungsten, platinum, palladium, stainless steels, 316L stainless steel, titanium, titanium alloys, Ni—Cr—Mo—W alloy, zirconium, zirconium alloys, HASTELLOY® alloys, Nickel alloys, MONEL® alloys, ICONEL® alloys, FERRALIUM® alloy, NITRONIC® alloys, CARPENTER® alloy, polyester, polyamide, aramid polyamide, polyacrylic, polyethylene, ultra-high molecular weight polyethylene, polypropylene, cellulose, protein, elastomeric, polytetrafluoroethylene, polybenzoxazol (PBO), polyvinylcarbazole, polyetherketone, carbon, bamboo charcoal, glass, or other conductive or non-conductive materials.

A textile article according to a third preferred embodiment of the invention is woven from a first single-strand yarn or a plied yarn by a textile process. The textile process can be a weaving process, a non-weaving process, a knitting process, a warp knitting process, a weft knitting process, or other textile processes. The plied yarn includes M second single-strand yarns which are doubled or twisted together, where M is an integer equal to or larger than 2. The first single-strand yarn and each second single-strand yarn a plurality both include a plurality of intimately associated staple fibers. The plurality of intimately associated staple fibers are made from N strands of first multi-filaments by stretching and controlled breaking, and then being spun by a spinning process, where N is a natural number. Within said one single-strand yarn of a sampling length, a ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length, to the total number of the staple fibers is equal to or greater than 60%. The sampling length is equal to or less than 10 meters. The setup fiber length is equal to or larger than 65 mm. A dispersion of a weight distribution in an average length of said one single-strand yarn is equal to or less than 60%. The N strands of first multi-filaments can be made of copper, CuNi alloys, CuNiSi alloys, CuNiZn alloys, CuNiSn alloys, CuCr alloys, CuAg alloys, CuW alloys, FeCrAl alloys, silver, gold, lead, zinc, aluminum, nickel, brass, phosphor bronze, beryllium copper, nichrome, tantalum, tungsten, platinum, palladium, stainless steels, 316L stainless steel, titanium, titanium alloys, Ni—Cr—Mo—W alloy, zirconium, zirconium alloys, HASTELLOY® alloys, Nickel alloys, MONEL® alloys, ICONEL® alloys, FERRALIUM® alloy, NITRONIC® alloys, CARPENTER® alloy, polyester, polyamide, aramid polyamide, polyacrylic, polyethylene, ultra-high molecular weight polyethylene, polypropylene, cellulose, protein, elastomeric, polytetrafluoroethylene, polybenzoxazol (PBO), polyvinylcarbazole, polyetherketone, carbon, bamboo charcoal, glass, or other conductive or non-conductive materials.

In one embodiment, a number of neps on a surface of the textile article according to the invention is equal to or less than 30/m².

Compared to the prior art, within the single-strand yarn of the sampling length or each single-strand yarn of the plied yarn, the ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length, to the total number of the staple fibers is equal to or greater than 60%, where the sampling length is equal to or less than 10 meters and the setup fiber length is equal to or larger than 65 mm. Moreover, the dispersion of the weight distribution in the average length of said one single-strand yarn is equal to or less than 60%. Therefore, the single-strand yarn and the plied yarn according to the invention have high strength and high diameter uniformity. Moreover, the textile article woven from the yarns made from the stretch-broken staple fibers according to the invention has better smoothness.

The advantage and spirit of the invention may be understood by the following recitations.

DETAILED DESCRIPTION OF THE INVENTION

The invention uses a plurality of intimately associated staple fibers made from multi-filaments by stretching and controlled breaking to spin into a single-strand yarn and a plied yarn, and a textile article is produced therefrom. In the invention, by controlling the stretch-breaking process, the dispersion of the length distribution of the staple fibers in the yarn is smaller, and the dispersion of the weight distribution of the average length of the yarn is smaller, so that the single-strand yarn and the plied yarn according to the invention have high strength and high diameter uniformity. The textile article woven from the yarns made from the stretch-broken staple fibers according to the invention has better smoothness. Some preferred embodiments and practical applications of this present invention would be explained in the following paragraph, describing the characteristics, spirit, and advantages of the invention.

A single-strand yarn according to a first preferred embodiment of the invention includes a plurality of intimately associated staple fibers. The plurality of intimately associated staple fibers are made from N strands of first multi-filaments by stretching and controlled breaking, and then are spun by a spinning process, where N is a natural number. The N strands of first multi-filaments are fed to a stretch-breaking machine to obtain a stretch-broken sliver, and then the stretch-broken sliver is fed into a spinning machine to be spun into the single-stranded yarn according to the invention.

In particular, within the single-strand yarn of a sampling length, a ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length, to the total number of the staple fibers is equal to or greater than 60%. The sampling length is equal to or less than 10 meters. The setup fiber length is equal to or larger than 65 mm. Moreover, a dispersion of a weight distribution in an average length of said single-strand yarn is equal to or less than 60%.

The N strands of first multi-filaments can be made of at least one selected from the group consisting of copper, CuNi alloys, CuNiSi alloys, CuNiZn alloys, CuNiSn alloys, CuCr alloys, CuAg alloys, CuW alloys, FeCrAl alloys, silver, gold, lead, zinc, aluminum, nickel, brass, phosphor bronze, beryllium copper, nichrome, tantalum, tungsten, platinum, palladium, stainless steels, 316L stainless steel, titanium, titanium alloys, Ni—Cr—Mo—W alloy, zirconium, zirconium alloys, HASTELLOY® alloys, Nickel alloys, MONEL® alloys, ICONEL® alloys, FERRALIUM® alloy, NITRONIC® alloys, CARPENTER® alloy, polyester, polyamide, aramid polyamide, polyacrylic, polyethylene, ultra-high molecular weight polyethylene, polypropylene, cellulose, protein, elastomeric, polytetrafluoroethylene, polybenzoxazol (PBO), polyvinylcarbazole, polyetherketone, carbon, bamboo charcoal, glass, or other conductive or non-conductive materials. Thereby, the single-strand yarn according to the invention can be composed of single-material fibers or mixed-material fibers, and not limited to high-performance fibers.

In one embodiment, a single-strand of second multi-filaments is formed of the at least one material forming the N strands of first multi-filaments. A first fineness of the single-strand yarn is identical to a second fineness of the single-strand of second multi-filaments. The single-strand yarn has a first strength, the single-strand of second multi-filaments has a second strength, and the first strength is equal to or greater than 70% of the second strength.

A plied yarn according to a second preferred embodiment of the invention includes M single-strand yarns, where M is an integer equal to or larger than 2. The M single-strand yarns are doubled or twisted together.

Each single-strand yarn a plurality includes a plurality of intimately associated staple fibers. The plurality of intimately associated staple fibers are made from N strands of first multi-filaments by stretching and controlled breaking, and then are spun by a spinning process, where N is a natural number. The N strands of first multi-filaments are fed to a stretch-breaking machine to obtain a stretch-broken sliver, and then the stretch-broken sliver is fed into a spinning machine to be spun into the single-stranded yarn.

In particular, within said one single-strand yarn of a sampling length, a ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length, to the total number of the staple fibers is equal to or greater than 60%. The sampling length is equal to or less than 10 meters. The setup fiber length is equal to or larger than 65 mm. Moreover, a dispersion of a weight distribution in an average length of said one single-strand yarn is equal to or less than 60%.

The N strands of first multi-filaments can be made of at least one selected from the group consisting of copper, CuNi alloys, CuNiSi alloys, CuNiZn alloys, CuNiSn alloys, CuCr alloys, CuAg alloys, CuW alloys, FeCrAl alloys, silver, gold, lead, zinc, aluminum, nickel, brass, phosphor bronze, beryllium copper, nichrome, tantalum, tungsten, platinum, palladium, stainless steels, 316L stainless steel, titanium, titanium alloys, Ni—Cr—Mo—W alloy, zirconium, zirconium alloys, HASTELLOY® alloys, Nickel alloys, MONEL® alloys, ICONEL® alloys, FERRALIUM® alloy, NITRONIC® alloys, CARPENTER® alloy, polyester, polyamide, aramid polyamide, polyacrylic, polyethylene, ultra-high molecular weight polyethylene, polypropylene, cellulose, protein, elastomeric, polytetrafluoroethylene, polybenzoxazol (PBO), polyvinylcarbazole, polyetherketone, carbon, bamboo charcoal, glass, or other conductive or non-conductive materials. Thereby, the plied yarn according to the invention can be composed of single-material fibers or mixed-material fibers, and not limited to high-performance fibers.

Similarly, in one embodiment, a single-strand of second multi-filaments is formed of the at least one material forming the N strands of first multi-filaments. A first fineness of each single-strand yarn is identical to a second fineness of the single-strand of second multi-filaments. Each single-strand yarn has a first strength, the single-strand of second multi-filaments has a second strength, and the first strength is equal to or greater than 70% of the second strength.

A textile article according to a third preferred embodiment of the invention is woven from a first single-strand yarn or a plied yarn by a textile process. The textile process can be a weaving process, a non-weaving process, a knitting process, a warp knitting process, a weft knitting process, or other textile process. The plied yarn includes M second single-strand yarns which are doubled or twisted together, where M is an integer equal to or larger than 2.

The first single-strand yarn and each second single-strand yarn a plurality both include a plurality of intimately associated staple fibers. The plurality of intimately associated staple fibers are made from N strands of first multi-filaments by stretching and controlled breaking, and then being spun by a spinning process, where N is a natural number. The N strands of first multi-filaments are fed to a stretch-breaking machine to obtain a stretch-broken sliver, and then the stretch-broken sliver is fed into a spinning machine to be spun into the single-stranded yarn.

In particular, within said one single-strand yarn of a sampling length, a ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length, to the total number of the staple fibers is equal to or greater than 60%. The sampling length is equal to or less than 10 meters. The setup fiber length is equal to or larger than 65 mm. Moreover, a dispersion of a weight distribution in an average length of said one single-strand yarn is equal to or less than 60%.

The N strands of first multi-filaments can be made of copper, CuNi alloys, CuNiSi alloys, CuNiZn alloys, CuNiSn alloys, CuCr alloys, CuAg alloys, CuW alloys, FeCrAl alloys, silver, gold, lead, zinc, aluminum, nickel, brass, phosphor bronze, beryllium copper, nichrome, tantalum, tungsten, platinum, palladium, stainless steels, 316L stainless steel, titanium, titanium alloys, Ni—Cr—Mo—W alloy, zirconium, zirconium alloys, HASTELLOY® alloys, Nickel alloys, MONEL® alloys, ICONEL® alloys, FERRALIUM® alloy, NITRONIC® alloys, CARPENTER® alloy, polyester, polyamide, aramid polyamide, polyacrylic, polyethylene, ultra-high molecular weight polyethylene, polypropylene, cellulose, protein, elastomeric, polytetrafluoroethylene, polybenzoxazol (PBO), polyvinylcarbazole, polyetherketone, carbon, bamboo charcoal, glass, or other conductive or non-conductive materials. Thereby, the first single-strand yarn and each second single-strand yarn according to the invention can be composed of single-material fibers or mixed-material fibers, and not limited to high-performance fibers.

Similarly, in one embodiment, a single-strand of second multi-filaments is formed of the at least one material forming the N strands of first multi-filaments. A first fineness of the first single-strand yarn or each second single-strand yarn is identical to a second fineness of the single-strand of second multi-filaments. In particular, the first single-strand yarn and each second single-strand yarn both have a first strength, the single-strand of second multi-filaments has a second strength, and the first strength is equal to or greater than 70% of the second strength.

In one embodiment, a number of neps on a surface of the textile article according to the invention is equal to or less than 30/m².

Compared to the prior art, within the single-strand yarn of the sampling length or each single-strand yarn of the plied yarn, which is equal to or less than 10 meters, the ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length, to the total number of the staple fibers is equal to or greater than 60%, where the sampling length is equal to or less than 10 meters. Moreover, the dispersion of the weight distribution in the average length of said one single-strand yarn is equal to or less than 60%. Therefore, the single-strand yarn and the plied yarn according to the invention having high strength and high diameter uniformity. Moreover, the textile article woven from the yarns made from the stretch-broken staple fibers according to the invention has better smoothness.

In one embodiment, the N strands of first multi-filaments according to the invention are formed of 316L stainless steel, and the textile article according to the invention is woven by a knitting process. The knitted textile article can be used as a separation cloth for covering molds and tempering or press-on rings which are utilized in the process of forming glass plates, or for covering the means of transport by which glass plates are moved during the forming process.

In an example, according to the invention, a double-strand of Kevlar® multi-filaments of 3000D is fed into a stretching machine to obtain a stretch-broken sliver, and then the stretch-broken sliver is fed to a spinning machine to be spun into a 30Ne single-yarn. The 30Ne single strand yarn is sampled at a sampling length of 1 meter. Within the single-strand yarn of the sampling length, the ratio of the number of staple fibers in the single-strand yarn, whose length equal to or greater than 60% of a setup fiber length of 65 mm, to the total number of the staple fibers is 60˜75%. The dispersion of the weight distribution of the average length of the yarn is controlled within 15˜25%. Compared to traditional yarns with a fineness equivalent to the fineness of the 30Ne single strand yarn of the example of the invention, a traditional 350D single-strand of Kevlar® multi-filaments has the strength of up to 10 kg. A traditional double-strand twisted yarn of 30Ne is made from a plurality of Kevlar® staple fibers, but its strength is only 3.6˜4 kg. The 30Ne single strand yarn of the example of the invention has the strength of 7.5˜8 kg. Obviously, the single-strand yarn and the plied yarn spun from staple fibers made by stretching and controlled breaking according to the invention have high strength and high diameter uniformity.

In another example, a double-strand yarn of 6.5Ne spun from a plurality of 316L stainless steel staple fibers made by stretching and controlled breaking according to the invention is woven into a knitted textile article. The knitted textile article can be used as a separation cloth for covering molds and tempering or press-on rings which are utilized in the process of forming glass plates, or for covering the means of transport by which glass plates are moved during the forming process. The 316L stainless steel double-strand yarn of 6.5Ne according to the invention is sampled at a sampling length of 1 meter. Within the double-strand yarn of the sampling length, the ratio of the number of staple fibers in the double-strand yarn, whose length equal to or greater than 60% of a setup fiber length of 65 mm, to the total number of the staple fibers is controlled within 65˜70%. The dispersion of the weight distribution of the average length of the yarn is controlled within 35˜45%. The number of neps or indurations on the surface of the knitted textile article in this example is measured to be less than 20 per square meter. Obviously, compared to the traditional textile article woven from the yarns made from the stretch-broken staple fibers of the prior art, the textile article woven from the yarns made from the stretch-broken staple fibers according to the invention has better smoothness.

From the above detailed description of the present invention, it can be clearly understood that the single-ply yarn according to the present invention or each ply yarn in the ply yarn itself is within a sampling length of not more than 10 meters, among multiple short fibers The ratio of the number of short fibers with a length equal to or greater than 60% of the set fiber length to the total number of multiple short fibers is equal to or greater than 60%, and the set fiber length is not less than 65 mm. In addition, the weight distribution dispersion of the average length of the single strand yarn is equal to or less than 60%. Therefore, according to the present invention, the single-ply yarn and the double-ply yarn have high strength and high diameter uniformity. In addition, textiles made from fibers formed into yarns and woven by the stretch-break method according to the present invention have better smoothness.

With the detailed description of the above preferred embodiments of the invention, it is clear to understand that within the single-strand yarn of the sampling length or each single-strand yarn of the plied yarn, the ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length, to the total number of the staple fibers is equal to or greater than 60%, where the sampling length is equal to or less than 10 meters and the setup fiber length is equal to or larger than 65 mm. Moreover, the dispersion of the weight distribution in the average length of said one single-strand yarn is equal to or less than 60%. Therefore, the single-strand yarn and the plied yarn according to the invention have high strength and high diameter uniformity. Moreover, the textile article woven from the yarns made from the stretch-broken staple fibers according to the invention has better smoothness.

With the example and explanations above, the features and spirits of the invention will be hopefully well described. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teaching of the invention. Accordingly, the above disclosure should be construed as limited only by the meters and bounds of the appended claims. 

What is claimed is:
 1. A single-strand yarn, comprising: a plurality of intimately associated staple fibers, being made from N strands of first multi-filaments by stretching and controlled breaking, and then being spun by a spinning process, N being a natural number, wherein within said single-strand yarn of a sampling length, a ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length, to the total number of the staple fibers is equal to or greater than 60%, the sampling length is equal to or less than 10 meters, the setup fiber length is equal to or larger than 65 mm, a dispersion of a weight distribution in an average length of said single-strand yarn is equal to or less than 60%, wherein the N strands of first multi-filaments are made of at least one selected from the group consisting of copper, CuNi alloys, CuNiSi alloys, CuNiZn alloys, CuNiSn alloys, CuCr alloys, CuAg alloys, CuW alloys, FeCrAl alloys, silver, gold, lead, zinc, aluminum, nickel, brass, phosphor bronze, beryllium copper, nichrome, tantalum, tungsten, platinum, palladium, stainless steels, 316L stainless steel, titanium, titanium alloys, Ni—Cr—Mo—W alloy, zirconium, zirconium alloys, HASTELLOY® alloys, Nickel alloys, MONEL® alloys, ICONEL® alloys, FERRALIUM® alloy, NITRONIC® alloys, CARPENTER® alloy, polyester, polyamide, aramid polyamide, polyacrylic, polyethylene, ultra-high molecular weight polyethylene, polypropylene, cellulose, protein, elastomeric, polytetrafluoroethylene, polybenzoxazol (PBO), polyvinylcarbazole, polyetherketone, carbon, bamboo charcoal, and glass.
 2. The single-strand yarn of claim 1, wherein a single-strand of second multi-filaments is formed of the at least one material forming the N strands of first multi-filaments, a first fineness of said single-strand yarn is identical to a second fineness of the single-strand of second multi-filaments, said single-strand yarn has a first strength, the single-strand of second multi-filaments has a second strength, and the first strength is equal to or greater than 70% of the second strength.
 3. A plied yarn, comprising: M single-strand yarns, being doubled or twisted together, M being an integer equal to or larger than 2, each single-strand yarn comprising: a plurality of intimately associated staple fibers, being made from N strands of first multi-filaments by stretching and controlled breaking, and then being spun by a spinning process, N being a natural number, wherein within said one single-strand yarn of a sampling length, a ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length, to the total number of the staple fibers is equal to or greater than 60%, the sampling length is equal to or less than 10 meters, the setup fiber length is equal to or larger than 65 mm, a dispersion of a weight distribution in an average length of said one single-strand yarn is equal to or less than 60%, wherein the N strands of first multi-filaments are made of at least one selected from the group consisting of copper, CuNi alloys, CuNiSi alloys, CuNiZn alloys, CuNiSn alloys, CuCr alloys, CuAg alloys, CuW alloys, FeCrAl alloys, silver, gold, lead, zinc, aluminum, nickel, brass, phosphor bronze, beryllium copper, nichrome, tantalum, tungsten, platinum, palladium, stainless steels, 316L stainless steel, titanium, titanium alloys, Ni—Cr—Mo—W alloy, zirconium, zirconium alloys, HASTELLOY® alloys, Nickel alloys, MONEL® alloys, ICONEL® alloys, FERRALIUM® alloy, NITRONIC® alloys, CARPENTER® alloy, polyester, polyamide, aramid polyamide, polyacrylic, polyethylene, ultra-high molecular weight polyethylene, polypropylene, cellulose, protein, elastomeric, polytetrafluoroethylene, polybenzoxazol (PBO), polyvinylcarbazole, polyetherketone, carbon, bamboo charcoal, and glass.
 4. The plied yarn of claim 3, wherein a single-strand of second multi-filaments is formed of the at least one material forming the N strands of first multi-filaments, a first fineness of said single-strand yarn is identical to a second fineness of the single-strand of second multi-filaments, said single-strand yarn has a first strength, the single-strand of second multi-filaments has a second strength, and the first strength is equal to or greater than 70% of the second strength.
 5. A textile article woven from a first single-strand yarn or a plied yarn by one selected from the group consisting of a weaving process, a non-weaving process, a knitting process, a warp knitting process, and a weft knitting process, the plied yarn comprising M second single-strand yarns which are doubled or twisted together, M being an integer equal to or larger than 2, the first single-strand yarn and each second single-strand yarn both comprising: a plurality of intimately associated staple fibers, being made from N strands of first multi-filaments by stretching and controlled breaking, and then being spun by a spinning process, N being a natural number, wherein within said one single-strand yarn of a sampling length, a ratio of the number of the staple fibers, whose length is equal to or greater than 60% of a setup fiber length, to the total number of the staple fibers is equal to or greater than 60%, the sampling length is equal to or less than 10 meters, the setup fiber length is equal to or larger than 65 mm, a dispersion of a weight distribution in an average length of said one single-strand yarn is equal to or less than 60%, wherein the N strands of first multi-filaments are made of at least one selected from the group consisting of copper, CuNi alloys, CuNiSi alloys, CuNiZn alloys, CuNiSn alloys, CuCr alloys, CuAg alloys, CuW alloys, FeCrAl alloys, silver, gold, lead, zinc, aluminum, nickel, brass, phosphor bronze, beryllium copper, nichrome, tantalum, tungsten, platinum, palladium, stainless steels, 316L stainless steel, titanium, titanium alloys, Ni—Cr—Mo—W alloy, zirconium, zirconium alloys, HASTELLOY® alloys, Nickel alloys, MONEL® alloys, ICONEL® alloys, FERRALIUM® alloy, NITRONIC® alloys, CARPENTER® alloy, polyester, polyamide, aramid polyamide, polyacrylic, polyethylene, ultra-high molecular weight polyethylene, polypropylene, cellulose, protein, elastomeric, polytetrafluoroethylene, polybenzoxazol (PBO), polyvinylcarbazole, polyetherketone, carbon, bamboo charcoal, and glass.
 6. The textile article of claim 5, wherein a single-strand of second multi-filaments is formed of the at least one material forming the N strands of first multi-filaments, a first fineness of the first single-strand yarn or each second single-strand yarn is identical to a second fineness of the single-strand of second multi-filaments, the first single-strand yarn and each second single-strand yarn both have a first strength, the single-strand of second multi-filaments has a second strength, and the first strength is equal to or greater than 70% of the second strength.
 7. The textile article of claim 6, wherein a number of neps on a surface of the textile article is equal to or less than 30/m².
 8. The textile article of claim 7, wherein the N strands of first multi-filaments are made of 316L stainless steel, the textile article is woven by the knitting process. 